Drawing machine

ABSTRACT

A drawing machine includes a plate, two series of rollers, two slides and two jaws. The plate defines two looped grooves. The series of rollers can roll in the looped grooves. The slides are movable on the plate. Each of the slides includes an upright side and an inclined edge for sliding on a related one of the series of rollers. Each of the jaws is attached to the upright side of a related one of the slides.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a drawing machine.

2. Related Prior Art

As disclosed in U.S. Pat. No. 6,953,136 B2, a conventional drawingmachine includes two wedges 9B, a jaw 5 attached to a side of each ofthe wedges 9B and a series of rotors in contact with another side ofeach of the wedges. Each series of rotors is disposed in and along arectilinear groove. When drawing proceeds, the series of rotors rotateagainst the wedges 9B so that the jaws 5 attached to the wedges 9Bsmoothly slide. However, the first and last ones of the rotors of eachseries could easily be worn out because of friction since the rotorsrotate in the rectilinear grooves, not roll. “Roll” means that an objectmoves in a direction while rotating about its own axis like a wheel doeson the ground.

The present invention is therefore intended to obviate or at leastalleviate the problems encountered in prior art.

SUMMARY OF INVENTION

According to the present invention, a drawing machine includes aclamping device, a drawing device and a driving device.

An advantage of the drawing machine according to the present inventionis reliability for not including any hydraulic or pneumatic cylinderthat would fluctuates in the pressure of the fluid and drags intransmission of the fluid.

Another advantage of the drawing machine according to the presentinvention is a simple structure including a small amount of elements.

Other advantages and features of the present invention will becomeapparent from the following description referring to the drawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration of thepreferred embodiment referring to the drawings.

FIG. 1 is a perspective view of a drawing machine according to thepreferred embodiment of the present invention.

FIG. 2 is an exploded view of the drawing machine shown in FIG. 1.

FIGS. 3 through 8 are top views of a portion of the drawing machineshown in FIG. 2 in various positions.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2, according to the preferred embodiment of thepresent invention, a drawing machine includes two tracks 10, a plate 40,a drawing device 20 and a clamping device 30. The tracks 1 0 extendparallel to each other. The platform 40 is movably disposed on thetracks 1 0. The clamping device 30 is provided on the top of the plate40 for clamping a rod or pipe. The drawing device 20 is used to move theplate 40, on which the clamp device 30 is provided, and therefore drawthe rod or pipe.

The drawing device 20 includes a driving element and two followingelements (FIG. 3). The following elements are attached to the bottom ofthe plate 40. The driving element includes a shaft and a ridge extendingon the shaft and acting as a cam. The ridge is engaged with thefollowing elements. As the shaft is rotated, the following elements aremoved by the ridge so that the clamping device is moved. Thus, the rodor pipe is drawn.

The clamping device 30 includes two rails 31, two slides 32, two jaws35, two rods, two series of rollers 34, two covers 36, a plate 37, ayoke and a cylinder.

The rails 31 extend on the top of the plate 40 so that the rails 31 getcloser to each other from a first end to a second end.

The slides 32 are movable along the rails 31. The slides 32 are in theform of a trapezoid, i.e., they include an upright side and an inclinedside opposite to the upright side. The upright side of each of theslides 32 extends parallel to that of the other slide 32. The inclinedside of each of the slides 32 is parallel to a related one of the rails31.

The jaws 35 are carried on the slides 32. Each of the jaws 35 is formedwith a concave side 351. The concave sides 351 define a cylindricalspace for receiving a half of a section of the rod or pipe.

The rods are raised from the slides 32.

Two looped grooves 33 are defined in the plate 40. Each of the series ofrollers 34 can roll in a related one of the looped grooves 33. Each ofthe series of rollers 34 is kept in a related one of the looped grooves33 by a related one of the covers 36.

The plate 37 is attached to the plate 40. The yoke is movable on theplate 37 and connected to the rods inserted through the plate 37. Thecylinder is a pneumatic or hydraulic cylinder for moving the yoke on theplate 37.

The cylinder can move the yoke. The yoke can move the rods. The rodscause the slides 32 to slide along the rails 31. The slides 32 move thejaws 35. The jaws 35 get closer to each other for clamping the rod orpipe.

Smooth sliding of and firm support to the slides 32 are ensured by therollers 34. As the rollers 34 are disposed in the looped grooves 33, therollers 34 can roll in the looped grooves 33, i.e., each of the rollers34 moves in a related one of the looped grooves 33 while rotating aboutits own axis. Thus, none of the rollers 34 is more vulnerable toabrasion than the others.

Referring to FIG. 3, the jaws 35 are separated from each other forreceiving the rod or pipe.

Referring to FIG. 4, the jaws 35 are moved towards each other forclamping the rod or pipe.

Referring to FIG. 5, the drawing device 20 is actuated so that theclamping device 30 is moved towards the first ends from the second endsof the rails 31. Thus, the rod or pipe is drawn, i.e., the rod or pipegets longer and thinner. Therefore, the jaws 35 get closer to each otherwhile the slides 32 slide further towards the second ends of the rails31 from the first ends. The rollers 34 ensure the smooth sliding of andfirm support to the slides 32.

Referring to FIG. 6, there is shown the end of the drawing of the rod orpipe by the drawing machine.

Referring to FIG. 7, the jaws 35 are moved away from each other for theremoving of the rod or pipe.

Referring to FIG. 8, the plate 40 is returned to its original position.

An advantage of the drawing machine according to the present inventionis reliability for not including any hydraulic or pneumatic cylinderthat would fluctuates in the pressure of the fluid and drags intransmission of the fluid. Another advantage of the drawing machineaccording to the present invention is a simple structure including asmall amount of elements.

The present invention has been described via the detailed illustrationof the preferred embodiment. Those skilled in the art can derivevariations from the preferred embodiment without departing from thescope of the present invention. Therefore, the preferred embodimentshall not limit the scope of the present invention defined in theclaims.

1. A drawing machine comprising: a plate defining two looped grooves;two series of rollers for rolling in the looped grooves; and two slidesmovable on the plate and each comprising an upright side for contactwith an object to be drawn and an inclined edge for sliding on a relatedone of the series of rollers.
 2. The drawing machine according to claim1 comprising two jaws each attached to the upright side of a related oneof the slides.
 3. The drawing machine according to claim 1 wherein theslides are in the form of a trapezoid.